From: Andreas Dilger Subject: Re: [PATCH -V4 08/11] vfs: Add new file and directory create permission flags Date: Sun, 2 Jan 2011 22:20:08 -0700 Message-ID: References: <1285332494-12756-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1285332494-12756-9-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20100924115423.530813c3@tlielax.poochiereds.net> <201009271514.00279.agruen@suse.de> <20110102232101.GB11955@thunk.org> Mime-Version: 1.0 (iPhone Mail 8C148a) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Cc: Andreas Gruenbacher , Jeff Layton , "Aneesh Kumar K.V" , "sfrench@us.ibm.com" , "ffilz@us.ibm.com" , "adilger@sun.com" , "sandeen@redhat.com" , "bfields@citi.umich.edu" , "linux-fsdevel@vger.kernel.org" , "nfsv4@linux-nfs.org" , "linux-ext4@vger.kernel.org" , "linux-kernel@vger.kernel.org" To: Ted Ts'o Return-path: In-Reply-To: <20110102232101.GB11955@thunk.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Actually, I think it is required by POSIX that EXDEV is returned when cross-linking files. For mv calling rename() at least it uses a return EXDEV to copy the file to the target filesystem instead of just giving up and returning an error. It may be other applications like tar have a similar dependency for link(). Cheers, Andreas On 2011-01-02, at 16:21, Ted Ts'o wrote: > I was going through some old patches in the ext4 patchwork list, and > came across this. It looks like this patch has never been applied to > mainline. If it's a "clear improvement", any reason not to submit it? > > Regards, > > - Ted > > On Mon, Sep 27, 2010 at 03:14:00PM +0200, Andreas Gruenbacher wrote: >> >> Ah, you mean this: >> >> --- a/fs/namei.c >> +++ b/fs/namei.c >> @@ -2450,7 +2450,9 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de >> if (!inode) >> return -ENOENT; >> >> - error = may_create(dir, new_dentry, S_ISDIR(inode->i_mode)); >> + if (S_ISDIR(inode->i_mode)) >> + return -EPERM; >> + error = may_create(dir, new_dentry, 0); >> if (error) >> return error; >> >> @@ -2464,8 +2466,6 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de >> return -EPERM; >> if (!dir->i_op->link) >> return -EPERM; >> - if (S_ISDIR(inode->i_mode)) >> - return -EPERM; >> >> error = security_inode_link(old_dentry, dir, new_dentry); >> if (error) >> >> This is a clear improvement; I don't think it matters that user-space will >> get -EPERM instead of -EXDEV when trying to hard-link a directory across >> devices. >> >> Thanks, >> Andreas > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html